4. a 1.34 kg pendulum is pulled back to a height of 0.965 m above the bottom of its swing and released.

a) what will be the speed of the pendulum at the bottom of its swing?
b) what will be the speed of the pendulum at a height of 0.679 m above the ground?
c) at what height will the pendulum have half of its original energy in the form of kinetic energy?

5. a 3050 kg roller coaster is at the base of the first hill when the chain lift grabs it and begins pulling it up the slope. the angle of the incline is 38.7 degrees, and the coefficient of roller coasting friction is 0.205. if the height of the first hill is 33.0 m and it took the roller coaster 55.4s to reach the top,

a) how much force is applied by the chain lift to bring the coaster to the top
b)how much work was done by the chain
c) what was the power exerted by the chain
d) what was the potential energy of the coaster at the top of the hill
e) why was the work done greater than the pe gained
f) neglecting friction on the way down, what would be the speed of the roller coaster at the bottom of the hill on the other side